Plants send small RNAs in extracellular vesicles to fungal pathogen to silence virulence genes

See allHide authors and affiliations

Science  08 Jun 2018:
Vol. 360, Issue 6393, pp. 1126-1129
DOI: 10.1126/science.aar4142

Defense cargo shuttles in vesicles

Plants can use small RNAs (sRNAs) to interfere with virulence factor gene expression in pathogens. Cai et al. show that the small mustard plant Arabidopsis shuttles defensive sRNAs into the necrotrophic fungus Botrytis cinerea via extracellular vesicles (see the Perspective by Thomma and Cook). The vesicles are associated with tetraspanin proteins, which can interact and form membrane microdomains. Several dozen different sRNAs targeting the pathogenic process were transported from Arabidopsis to B. cinerea in a selective manner.

Science, this issue p. 1126; see also p. 1070


Some pathogens and pests deliver small RNAs (sRNAs) into host cells to suppress host immunity. Conversely, hosts also transfer sRNAs into pathogens and pests to inhibit their virulence. Although sRNA trafficking has been observed in a wide variety of interactions, how sRNAs are transferred, especially from hosts to pathogens and pests, is still unknown. Here, we show that host Arabidopsis cells secrete exosome-like extracellular vesicles to deliver sRNAs into fungal pathogen Botrytis cinerea. These sRNA-containing vesicles accumulate at the infection sites and are taken up by the fungal cells. Transferred host sRNAs induce silencing of fungal genes critical for pathogenicity. Thus, Arabidopsis has adapted exosome-mediated cross-kingdom RNA interference as part of its immune responses during the evolutionary arms race with the pathogen.

View Full Text

Stay Connected to Science